Pulverized fuel furnace



June 2, 1931. A. RUNKWITZ PULVERIZED' FUEL FURNACE Filed July 28, 1930 Patented June 2, 1931 UNITED STATES. PATIENT OFFICE ARTHUR mmxwrrz, or KIEL-ELMSCHENHAGEN, emummr, AssIenon T0 FRIED. xnurr GERMANIAWERFT AKTIENGESELLSCHAFT, or KIEL-GAARDEN, GERMANY PUIiVERIZED FUEL FURNACE Applicationflled July 28, 1980, Serial No. 471,288, and in Germany August 9, 1929.

The invention relates to a burner arrangement for pulverized fuel furnaces and has for its object to secure a particularly satisfactory intermixing of the pulverized fuel and the air of combustion; Thisobject is obtained according to the invention primarily by the fact that the main quantity of the fuel and air mixture is fed to the combustion chamber through a plurality of bent pipes arranged in a circle, each bent pipe being surounded by a wider bent pipe through which additional air is supplied.

In order that the invention can be more readily understood, a preferred embodiment of the same is illustrated by way of example in the accompanying drawings, in which Figure l is a sectional side view of the burner arrangement as applied to the flue of a cylindrical boiler,

Figure 2 shows the burner head, on enlarged scale,

Figure '3 is a front view of the burner head, seen from the right, on the scale of Figure 2, and

Figure 4 is a section along a cylindrical plane as indicated by 4.-4 of Figure 3.

The pulverized fuel burner is centrally mounted on a removable furnace front B and comprises an external tubular jacket C closed toward the fire chamber by a burner plate D. Within the jacket 0 is arranged concentrically a narrow cylindrical tube E i and a wider conical tube F. The latter is 1 closed toward the fire chamber by a front plate G through which projects tube E. The

burner plate D is connected to the front plate G by bridge pieces or the like and is urged against the front end of the tubes C and F by a cap H by means of a bayonet joint.

The inner tube E servesto supply that portion of the pulverized fuel-air mixture that feeds the ignition flame. This tube E opens toward the fire chamber into a roseshapedburner which produces only a com paratively short ignition flame, as marked in a dotted line in Figure 2. The main quantity of the pulverized fuel-air mixture is supplied through the annular space existing between thev tubes E and F. Exit of the pulverized fuel-air mixture into the fire chamber takes place through laterally bent pipes K mounted on the front plate G and surrounded by likewise bent wider air pipes L fixed to the burner plate D. The pipes L communicate with the annular space existing between the tubes C and F and serving to supply additional air of combust'i'on. The pipes K and L are arranged in a circle and their mouths, as to be seen from the drawing, have a direction such as to produce a whirl motion in the flue of the boiler.

In the described boiler the entire pulverized fuel-air mixture is decomposed into a plurality of individual jets each of whichhas allotted to it the required quantity of additional air of combustion which entirely envelops the jet of the'mixture, so that a very satisfactory intermixing of the pulverized fuel and the air of combustion is obtained. The centrally arranged ignition burner reliably secures ignition of the main flame. Furthermore, the ignition flame can serve as sole source of heat when the boiler is not in full operation. Finally, the peculiar arrangement of the burner results st1ll in-the fact that coarser particles of pulverized fuel that are cast outward by centrifugal'force, traverse through the furnace on a longer way along the circumference of the flue and have thus the opportunity to burn out completely.

Owing to the additional air being forced to pass between the front walls D and G of the tubes C and F and to escape through the bent pipes L, the entire burner head both is protected against backward heat radiation from the fire chamber and intensively cooled, and, besides, the additional air of combustion is highly preheated.

What I claim and desire-to secure by Letters Patent is 1. A pulverized fuel burner comprising a burner plate, a plurality of individual laterally bent burner pipes circularly arranged on this plate, larger pipes each surcorrespondingly, a tube adapted to supply pulverized fuel-air mixture and communicating -with all of said burner pipes, and another tube adapted to supply additional air of combustion and communicating with all of said larger pipes.

2. A pulverized fuel burner comprising a burner plate, a plurality of individual laterally bent burner pipes circularly arrangedon this plate, a tube closed on its forward end by said plate and adapted to supply pulverized fuel-air mixture, another plate arranged spacedly in front of said burner plate, pipes corresponding in number to said burner pipes and laterally bent and mounted on said other plate so as to surround said burner pipes, and, another tube closed on its forward end by said other plate and adapted to supply additional air to said surrounding pipes.

3. A pulverized fuel burner comprising a burner plate, a plurality of individual laterally bent burner pipes circularly arranged on this plate, a tube closed on its forward end by said plate and adapted to supply pulverized fuel-air mixture, another plate arranged spacedly in front of said burner plate, pipes corresponding in number to said burner pipes and laterally bent and mounted on said other plate so as to surround said burner pipes, another tube closed on its forward end by said other plate and adapted to supply additional air to said surrounding pipes, an ignition burner centrally arranged on said other plate, a third tube arranged Within said first-named tube and adapted to supply pulverizedfuel-air mixture to said ignition burner.

The foregoing specification signd at Hamburg, Germany, this 12th day of July,

ARTHUR RUNKWITZ. 

